package Solutiong1;

public class PalindromeList {
    public boolean chkPalindrome(ListNode A) {
        if(A==null){
            return true;
        }
        ListNode slow=A;
        ListNode fast=A;
        while(fast!=null&&fast.next!=null){
            fast=fast.next.next;
            slow=slow.next;
        }
        ListNode cur=slow.next;
        while(cur!=null){
            ListNode curN=cur.next;
            cur.next=slow;
            slow=cur;
            cur=curN;
        }
        while(A!=slow){
            if(A.val!=slow.val){
                return false;
            }
            if(A.next==slow){
                return true;
            }
            A=A.next;
            slow=slow.next;
        }
        return true;
    }
}

public class s2 {

}
